Search results for "trophic niche"
showing 10 items of 20 documents
From clear lakes to murky waters – tracing the functional response of high-latitude lake communities to concurrent ‘greening’ and ‘browning’
2019
Climate change and the intensification of land use practices are causing widespread eutrophication of subarctic lakes. The implications of this rapid change for lake ecosystem function remain poorly understood. To assess how freshwater communities respond to such profound changes in their habitat and resource availability, we conducted a space-for-time analysis of food-web structure in 30 lakes situated across a temperature-productivity gradient equivalent to the predicted future climate of subarctic Europe (temperature +3 degrees C, precipitation +30% and nutrient +45 mu g L-1 total phosphorus). Along this gradient, we observed an increase in the assimilation of pelagic-derived carbon from…
Lake size and fish diversity determine resource use and trophic position of a top predator in high-latitude lakes
2015
Prey preference of top predators and energy flow across habitat boundaries are of fundamental importance for structure and function of aquatic and terrestrial ecosystems, as they may have strong effects on production, species diversity, and food-web stability. In lakes, littoral and pelagic food-web compartments are typically coupled and controlled by generalist fish top predators. However, the extent and determinants of such coupling remains a topical area of ecological research and is largely unknown in oligotrophic high-latitude lakes. We analyzed food-web structure and resource use by a generalist top predator, the Arctic charr Salvelinus alpinus (L.), in 17 oligotrophic subarctic lakes…
Unravelling diet composition and niche segregation of colonial waterbirds in a Mediterranean wetland using stable isotopes
2021
Trophic niche features influence microplastic ingestion in Mediterranean fish species
2022
Widespread microplastic (MP) contamination in the marine environment has raised global concern in the last decade. Scientific evidence of the adverse effects of MP on organisms is growing fast and there is urgent need to fulfil the knowledge gaps about the trophic drivers that lead to such contamination processes and resulting impacts. Fish are considered good bioindicators of MP contamination due to their easy availability, high ecological and commercial value, however our understanding of how trophic niche influences MP ingestion is limited. Here, we investigated the occurrence and abundance of MP in the gastrointestinal tract of 8 commercial fish species (Boops boops, Engraulis encrasico…
Plasticity in the trophic niche of an invasive ant explains establishment success and long‐term coexistence
2021
Invasive species are one of the main threats to biodiversity worldwide and the processes enabling their establishment and persistence remain poorly understood. In generalist consumers, plasticity in diet and trophic niche may play a crucial role in invasion success. There is growing evidence that invasive ants, in particular, occupy lower trophic levels in their introduced range compared to the native one, but evidences remain fragmented. We conducted stable isotope analysis at five locations distributed on two continents to infer the trophic position of the invasive ant Formica paralugubris in the native and introduced part of the range. This species forms large colonies and can be a vorac…
Dependence of Arctic char (Salvelinus alpinus L.) on littoral and pelagic energy sources in a subarctic lake, Saanajärvi
2007
Past and current distribution of Charaxes jasius jasius (Linnaeus, 1767) (Lepidoptera Nymphalidae) in Sicily in relation to its host plant, Arbutus u…
2022
The authors provide an updated overview of the past and present regional distribution of the two-tailed Pasha Charaxes jasius jasius (Linnaeus, 1767) (Lepidoptera Nymphalidae) and its host plant, the strawberry tree Arbutus unedo L. Most of the occurrence data reported in the entomological literature was confirmed, and several new populations have been recently dis- covered. The distribution pattern of the insect and its host plant overlap almost perfectly. C. jasius jasius is more abundant and forms large and stable populations on the Peloritani Mts. and in some areas of the Madonie Mountains. The high number of new records of C. jasius jasius suggests that the species is experiencing a sp…
Angular roughshark Oxynotus centrina (Squaliformes: Oxynotidae) in captivity feeding exclusively on elasmobranch eggs: an overlooked feeding niche or…
2015
A specimen of angular roughshark Oxynotus centrina has been kept successfully in captivity for the first time. Over a period of 24 months, the specimen preyed exclusively on the contents of elasmobranch egg cases, suggesting a specialized trophic niche.
Population structure, life cycle, and trophic niche of the glacial relict amphipod, Gammaracanthus lacustris , in a large boreal lake
2019
Ontogenetic trophic segregation between two threatened smooth-hound sharks in the Central Mediterranean Sea
2020
AbstractElasmobranchs are among the species most threatened by overfishing and a large body of evidence reports their decline around the world. As they are large predators occupying the highest levels of marine food webs, their removal can alter the trophic web dynamic through predatory release effects and trophic cascade. Suitable management of threatened shark species requires a good understanding of their behaviour and feeding ecology. In this study we provide one of the first assessments of the trophic ecology of the “vulnerable” smooth-hounds Mustelus mustelus and M. punctulatus in the Central Mediterranean Sea, based on stomach contents and stable isotope analyses. Ontogenetic diet ch…